I have 4 Mitsubishi FH series wall units and I was wondering if anyone knows if the condensate line comes with a built-in trap in the unit. The lines don’t have one on the outside. The corrugated flex lines run inside PVC outside and I’d install a running trap but don’t want a double trap situation. 
I know it’ll freeze in winter if I don’t drain it but since heat mode doesn’t produce condensation I don’t think it’d be an issue. Thanks in advance